diff options
Diffstat (limited to 'drivers/iommu/amd_iommu.c')
| -rw-r--r-- | drivers/iommu/amd_iommu.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 6edbd0edcae..3a00b5ce73a 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -274,6 +274,18 @@ static void swap_pci_ref(struct pci_dev **from, struct pci_dev *to) *from = to; } +static struct pci_bus *find_hosted_bus(struct pci_bus *bus) +{ + while (!bus->self) { + if (!pci_is_root_bus(bus)) + bus = bus->parent; + else + return ERR_PTR(-ENODEV); + } + + return bus; +} + #define REQ_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF) static struct pci_dev *get_isolation_root(struct pci_dev *pdev) @@ -300,14 +312,9 @@ static struct pci_dev *get_isolation_root(struct pci_dev *pdev) * Finding the next device may require skipping virtual buses. */ while (!pci_is_root_bus(dma_pdev->bus)) { - struct pci_bus *bus = dma_pdev->bus; - - while (!bus->self) { - if (!pci_is_root_bus(bus)) - bus = bus->parent; - else - goto root_bus; - } + struct pci_bus *bus = find_hosted_bus(dma_pdev->bus); + if (IS_ERR(bus)) + break; if (pci_acs_path_enabled(bus->self, NULL, REQ_ACS_FLAGS)) break; @@ -315,7 +322,6 @@ static struct pci_dev *get_isolation_root(struct pci_dev *pdev) swap_pci_ref(&dma_pdev, pci_dev_get(bus->self)); } -root_bus: return dma_pdev; } |